Util/MultiReader.cs

   1 //
   2 // MultiReader.cs
   3 //
   4 // Copyright (C) 2004 Novell, Inc.
   5 //
   6
   7 //
   8 // Permission is hereby granted, free of charge, to any person obtaining a copy
   9 // of this software and associated documentation files (the "Software"), to deal
  10 // in the Software without restriction, including without limitation the rights
  11 // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  12 // copies of the Software, and to permit persons to whom the Software is
  13 // furnished to do so, subject to the following conditions:
  14 //
  15 // The above copyright notice and this permission notice shall be included in all
  16 // copies or substantial portions of the Software.
  17 //
  18 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  19 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  20 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  21 // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  22 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  23 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  24 // SOFTWARE.
  25 //
  26
  27 using System;
  28 using System.Collections;
  29 using System.IO;
  30 using System.Text;
  31
  32 namespace Beagle.Util {
  33
  34         public class MultiReader : TextReader {
  35
  36                 Queue readers = new Queue ();
  37
  38                 public MultiReader ()
  39                 { }
  40
  41                 public void Add (TextReader reader)
  42                 {
  43                         readers.Enqueue (reader);
  44                 }
  45
  46                 public int Count {
  47                         get { return readers.Count; }
  48                 }
  49
  50                 private TextReader Current {
  51                         get {
  52                                 if (readers.Count == 0)
  53                                         return null;
  54                                 return (TextReader) readers.Peek ();
  55                         }
  56                 }
  57
  58                 private void Next ()
  59                 {
  60                         if (readers.Count > 0)
  61                                 readers.Dequeue ();
  62                 }
  63
  64                 public override void Close ()
  65                 {
  66                         while (Current != null) {
  67                                 Current.Close ();
  68                                 Next ();
  69                         }
  70                 }
  71
  72                 public override int Peek ()
  73                 {
  74                         while (Current != null) {
  75                                 int peek = Current.Peek ();
  76                                 if (peek != -1)
  77                                         return peek;
  78                                 Next ();
  79                         }
  80
  81                         return -1;
  82                 }
  83
  84                 public override int Read ()
  85                 {
  86                         while (Current != null) {
  87                                 int read = Current.Read ();
  88                                 if (read != -1)
  89                                         return read;
  90                                 Next ();
  91                         }
  92
  93                         return -1;
  94                 }
  95
  96                 public override int Read (char[] buffer, int index, int count)
  97                 {
  98                         int total = 0;
  99                         while (Current != null && count > 0) {
 100                                 int actual = Current.Read (buffer, index + total, count);
 101                                 if (actual < count)
 102                                         Next ();
 103                                 count -= actual;
 104                                 total += actual;
 105                         }
 106                         return total;
 107                 }
 108
 109                 public override int ReadBlock (char[] buffer, int index, int count)
 110                 {
 111                         return Read (buffer, index, count);
 112                 }
 113
 114                 public override string ReadLine ()
 115                 {
 116                         while (Current != null) {
 117                                 string str = Current.ReadLine ();
 118                                 if (str != null)
 119                                         return str;
 120                                 Next ();
 121                         }
 122
 123                         return null;
 124                 }
 125
 126                 public override string ReadToEnd ()
 127                 {
 128                         StringBuilder all = new StringBuilder ("");
 129
 130                         while (Current != null) {
 131                                 string str = Current.ReadToEnd ();
 132                                 if (str != null)
 133                                         all.Append (str);
 134                                 Next ();
 135                         }
 136
 137                         return all.ToString ();
 138                 }
 139
 140
 141
 142         }
 143 }